Congestion problems occur sometimes in communication networks comprising backhaul networks connected to radio access networks.
FIG. 1 is an illustration of a communications network. Said communications network 10 comprises a backhaul network 12, even denoted transport network, and a Radio Access Network, RAN, 14. As understood by the skilled person, said communications network 10 may comprise more than one backhaul network 12 and more than one RAN 14.
A communications network 10 provides transportation in two directions, uplinks and downlinks, for users having mobile User Equipment 24. The RAN 14 comprises one or more Radio Base Stations, RBSs, 20 or Access Points, APs, for enabling access for the UEs 24 via radio links in the air interface. These RBSs or APs are considered as nodes in the RAN, which nodes hereafter is denoted as RBS regardless if they comprise a RBS or an AP.
The mobile broadband traffic is growing, but the cost of building new transport network for small cells is very high. It is therefore desirable to solve capacity problems in the existing networks.
The tightest part in a radio network is not always the radio link. Transport/Backhaul/backbone/core networks, especially involving aggregation network structure, and the last mile can become a bottleneck. Operators may not be willing to build new networks for each of new small cell RBS sites; instead they are using existing networks, where overbooking is common, based on statistical multiplexing technique. E.g. all users are not using the network at same time
With the small cell backhaul the congestion problem get even worst because a small cell backhaul network can be out of the control of the operator. E.g. all or a part of the backhaul network is leased or Internet is used as the backhaul.